I am going to line the lid with plastic so the cement doesn't bond to the metal. The metal lid will not be a part of the finished oven.
Then I'm going to shape chicken wire to the lid and mold a half inch layer of casting refractory cement to it.
Once this cures, I am going to apply a half inch of a more insulative mix to the outside of the casted cement lid (possibly a lighter, 50/50 perlite mix. I'm open to opinions since I have never laid a brick or used cement before.
Since the weight is already getting up there, I want to make a strong dome, but light-weight and able to retain heat and reflect it back.
Think pizza hacker with a stucco finish haha. I would build a full oven, but I'm keeping things under $100 the wife wants something I can wheel out of the way if needed.
Any help would be appreciated.